Author: Facundo Zaffaroni, Subject Matter Expert in Biostatistics & AI, IDDI
Based on a podcast conversation with Marc Buyse, Founder and Chief Scientific Officer, IDDI
There is one factor that can quietly undermine a clinical trial’s credibility. It isn’t about clinical study design or biostatistics.
It’s an operational bias that can arise even in the most well-intentioned teams. Fortunately, it’s also one that an experienced IDMC (Independent Data Monitoring Committee) and SDAC (Statistical Data Analysis Center) can help prevent.
The Risk
Many biotech companies operate with small, highly committed teams focused on bringing their innovations to patients as efficiently as possible. However, these teams often work under close attention from boards and investors who are eager to understand how a trial is progressing and whether it shows promise. This pressure for reassurance can lead to subtle but serious risks. Even if everyone knows that unblinded data must remain confidential, the desire to “get a feel” for how things are going can result in requests for updates that go beyond what is appropriate during an ongoing trial.
That’s precisely where the IDMC plays its crucial role: protecting the data, the trial, and the company.
If anyone connected to the sponsor or its stakeholders gains access to ongoing trial data (even indirectly), regulatory agencies such as the FDA, EMA, or PMDA (Japan) may determine that operational bias has occurred. In that case, the trial results may no longer be acceptable for regulatory submission. Even in open-label clinical trials, it remains best practice to operate as if the trial were blinded and to avoid examining or discussing treatment comparisons during the trial. Once unblinded information is seen, it can influence decisions (consciously or not), and regulators are adept at recognizing when this has occurred.
Sponsors may sometimes ask:
“Why can’t we, as a biotech company, take a quick look at the data?”
“Couldn’t the IDMC at least indicate which treatment seems to be performing better?”
These are natural questions, especially in early development where momentum and investor confidence are critical. But the answer must remain clear: sponsors and their representatives cannot view or infer ongoing results. The IDMC must never reveal comparative data, even in general terms. To preserve trial integrity, no one within the sponsor organization, regardless of role, should view or be told which treatment is performing better. This includes investors and board members.
Best Practice
To ensure integrity and compliance, access to unblinded data must remain completely independent from the sponsor. IDMC members work with an SDAC, such as IDDI, where only designated statisticians have access to unblinded data. The SDAC prepares the analyses and confidential reports for the IDMC. The IDMC then reviews the findings and provides recommendations, not data, to the sponsor, maintaining a strict separation that protects both scientific credibility and regulatory trust.
Watch the full conversation
To find out more about IDMCs, watch the full podcast, where Marc Buyse shares insights on the strategic benefits for companies of all sizes, common mistakes, and explains why IDMCs are central to trial credibility and regulatory trust.
IDDI has assisted more than 325 IDMCs worldwide, helping sponsors reduce risk and strengthen their clinical programs. If you would like to learn more, get in touch.